Synthesis and characterization of cation exchange membrane based on Polyaniline Bi(III)tungstophosphate nanocomposite: its application as Ni(II) selective electrode

In the present study an organic-inorganic nanocomposite ion exchanger Polyaniline Bi(III)tungstophosphate was synthesized via sol-gel process showing excellent ion exchange capacity (IEC–3.2 meqg⁻¹). It showed high DC electrical conductivity (3.35 S cm⁻¹) with good retention capability up to 120 °C under isothermal and cyclic ageing experiments. This nanocomposite was utilized in preparation of heterogeneous ion exchange membrane (IEC–1.2 meqg⁻¹) by solution casting method. The materials were characterized by SEM with EDX, TEM, XRD, FTIR, and TGA-DTA. A Ni²⁺ selective membrane electrode was fabricated, and its various parameters like detection limit (6.3 × 10⁻⁸ M), linear response range (6.3 × 10⁻⁸ M to 1.0 × 10⁻¹ M), response time (35 s) and working pH range (4–8) were calculated. It was employed as an indicator electrode in the potentiometric titration of Ni²⁺. (paper)